<template>
    <h3>Header</h3>
</template>

<!-- 加scoped 不然样式会在全局都生效-->
<style scoped>
h3{
width: 100%;
height: 100px;
border: 5px solid #999;
text-align: center;
line-height: 100px;
box-sizing: border-box;
}

</style>
